Adjustable fan volute, test fan and magnetic member thickness design method

Abstract

The application relates to a type-line-adjustable fan volute, a test fan and a magnetic member thickness design method, which can improve fan performance and significantly reduce design iteration time and manufacturing cost. The type-line-adjustable fan volute comprises a volute frame including a pair of end covers arranged at intervals, each end cover being provided with an air inlet and a plurality of adjusting grooves arranged around the air inlet; a volute ring wall including an elastic side wall movably arranged between the two end covers and a volute tongue fixedly arranged between the two end covers; one end of the elastic side wall is fixedly connected to the two end covers to form an air outlet together with the volute tongue; the other end of the elastic side wall sequentially passes through the plurality of adjusting grooves and is wound in the volute tongue to form a winding drum; and a plurality of adjusting rods, two ends of each adjusting rod are respectively adjustably inserted into the opposite adjusting grooves of the two end covers and are located outside the elastic side wall and magnetically attract the elastic side wall to adjust the type line of the volute ring wall.

Description

Technical Field

[0001] This invention relates to the field of centrifugal fan technology, and in particular to a method for designing the thickness of an adjustable profile fan volute, a test fan, and magnetic components. Background Technology

[0002] In the development and design of range hoods, the experimental testing of centrifugal fans plays a crucial role. This is because such testing not only ensures that the fan performance meets specific requirements but also helps optimize the design, improve energy efficiency, and reduce noise. Ultimately, through precise testing, engineers can verify and improve design solutions, thereby producing more efficient and user-friendly range hoods.

[0003] However, in the traditional centrifugal fan testing process, the design and manufacturing of the volute structure faces a significant challenge. Specifically, whenever test data reveals design deficiencies and a new design solution needs to be explored, engineers must fabricate an entirely new volute. This not only leads to long prototyping times but also significantly increases the testing cycle, thereby impacting product launch time and significantly increasing centrifugal fan development costs. Especially in today's increasingly competitive market, such delays and increased costs can have a serious negative impact on a company's market position. Summary of the Invention

[0004] Therefore, it is necessary to address the problems of long testing cycles and high development costs of volute structures. This invention provides a method for designing the thickness of a profile-adjustable fan volute, a test fan, and magnetic components, which can improve fan performance and significantly reduce design iteration time and manufacturing costs.

[0005] In one embodiment of this application, the present invention provides a profile-adjustable fan casing, comprising:

[0006] The volute frame includes a pair of end caps arranged at intervals, each end cap having an air inlet and a plurality of adjustment slots arranged around the air inlet;

[0007] The volute annular wall includes an elastic sidewall movably disposed between the two end caps and a volute tongue fixedly disposed between the two end caps; one end of the elastic sidewall is fixedly connected to the two end caps to form an air outlet with the volute tongue; the other end of the elastic sidewall passes sequentially through a plurality of adjustment grooves and is wound into the volute tongue to form a roll; and

[0008] Multiple adjusting rods, each having its two ends adjustablely inserted into opposing adjusting slots on two end caps, and located outside the elastic sidewalls, with magnetic force pulling the elastic sidewalls to adjust the profile of the volute annular wall.

[0009] According to one embodiment of this application, the adjusting rod includes a screw, a nut that matches the screw, and a magnetic element fixed to the screw and magnetically attracting the elastic sidewall; the screw passes through the two opposing adjusting slots on the end caps, and the nut is threadedly connected to the screw.

[0010] According to one embodiment of this application, the elastic sidewall is a magnetic element; the magnetic element is a magnet.

[0011] According to one embodiment of this application, the screw has a mounting surface facing the elastic sidewall, and the magnetic element is attached to the mounting surface of the screw.

[0012] According to one embodiment of this application, the adjusting rod further includes a buffer pad attached to the magnetic element, the buffer pad being located between the magnetic element and the elastic sidewall to conform to the elastic sidewall.

[0013] According to one embodiment of this application, the length of the magnetic element is equal to the width of the elastic sidewall; the width of the magnetic element is equal to the diameter of the screw.

[0014] According to one embodiment of this application, a notch is provided on the screw at a location corresponding to the elastic sidewall to accommodate the magnetic component, so as to provide the mounting surface through the bottom of the notch; the width of the mounting surface is equal to the diameter of the screw.

[0015] According to one embodiment of this application, the thickness of the magnetic element satisfies the following relationship:

[0016]

[0017] In the formula: t c E is the thickness of the magnetic component; E is the elastic modulus of the elastic sidewall; I is the moment of inertia of the elastic sidewall; b is the outer limiting curvature of the elastic sidewall near the adjusting rod of the volute tongue; a is the inner limiting curvature of the elastic sidewall near the adjusting rod of the volute tongue; L1 is the vertical distance between the adjusting rod near the volute tongue and the volute tongue; L2 is the vertical distance between the adjusting rod near the volute tongue and the adjacent adjusting rod; t h K1 is the thickness of the buffer pad; K2 is the safety factor; K3 is the empirical coefficient based on the magnetic component; ρ is the density of the magnetic component; L is the length of the magnetic component; and B is the width of the magnetic component.

[0018] According to one embodiment of this application, the adjustable profile fan casing further includes a pair of sealing gaskets, the two sealing gaskets being respectively fixed to the inner walls of the two end caps and located between the end caps and the casing annular wall to fill the gap between the end caps and the casing annular wall.

[0019] According to another aspect of this application, an embodiment of this application further provides a test fan, comprising:

[0020] The adjustable profile fan casing described above; and

[0021] An impeller is rotatably mounted on the volute of the profile-adjustable fan.

[0022] According to another aspect of this application, an embodiment of this application further provides a method for designing the thickness of a magnetic component, including the steps of:

[0023] Based on the moment of inertia of the elastic sidewall and the curvature formula of the beam bending, the magnetic force required for the elastic sidewall to change from the inner limit curvature to the outer limit curvature is calculated using a magnetic force calculation model.

[0024] Based on the thickness of the buffer pad and the length, width, and density of the magnetic component, the magnetic force exerted by the magnetic component on the elastic sidewall is calculated using an empirical magnetic force model; and

[0025] Based on the fact that the magnetic force applied by the magnetic component to the elastic sidewall is greater than or equal to the magnetic force required for the elastic sidewall, a thickness relationship is constructed to solve for the thickness of the magnetic component.

[0026] According to one embodiment of this application, the magnetic force calculation model is as follows:

[0027]

[0028] Wherein: F 磁 The magnetic force required for the elastic sidewall to change from the inner limiting curvature a to the outer limiting curvature b; E is the elastic modulus of the elastic sidewall; I is the moment of inertia of the elastic sidewall; L1 is the vertical distance between the adjusting rod adjacent to the volute tongue and the volute tongue; L2 is the vertical distance between the adjusting rod adjacent to the volute tongue and the adjacent adjusting rod; K1 is the safety factor.

[0029] According to one embodiment of this application, the empirical magnetic force model is as follows:

[0030]

[0031] Among them, F 磁' is the magnetic force exerted by the magnetic component on the elastic sidewall; K2 is an empirical coefficient based on the magnetic component; K3 is an empirical coefficient based on the elastic sidewall; ρ is the density of the magnetic component; L is the length of the magnetic component; B is the width of the magnetic component; t c t represents the thickness of the magnetic component. h This refers to the thickness of the cushioning pad.

[0032] In summary, during testing, the adjustable fan casing of this application allows each adjusting rod to be fixed at the required position on the corresponding adjusting groove according to the casing design requirements. Under the magnetic traction of the adjusting rod, the elastic sidewall remains in contact with it, enabling precise adjustment of the casing ring wall's profile and ensuring consistency between the actual and designed profile. If, after testing and analysis, deficiencies in the previous design necessitate a new design, simply adjusting the fixed position of the adjusting rod on the corresponding adjusting groove according to the new design requirements achieves the casing ring wall profile adjustment. This eliminates the need for engineers to fabricate a completely new casing, significantly shortening the testing cycle, reducing development costs, and preventing delays in product launch. Especially in today's increasingly competitive market, the substantial reduction in testing cycle and cost will have a positive impact on a company's market position. Attached Figure Description

[0033] Figure 1 This is a perspective view of an adjustable fan casing according to an embodiment of this application;

[0034] Figure 2 An exploded view of the profile-adjustable fan casing of the above-described embodiment of this application is shown;

[0035] Figure 3 An enlarged schematic diagram of the adjusting rod in the volute of the profile-adjustable fan of the above embodiment of this application is shown;

[0036] Figure 4 An exploded view of the adjusting rod according to the above embodiments of this application is shown;

[0037] Figure 5 A cross-sectional schematic diagram of the profile-adjustable fan casing of the above embodiment of this application is shown;

[0038] Figure 6 It shows Figure 5 The diagram shows an enlarged view of part A in the volute of an adjustable-profile fan.

[0039] Figure 7 It shows Figure 5 The diagram shows an enlarged view of part B in the volute of the adjustable profile fan.

[0040] Figure 8 This is a schematic flowchart of a magnetic component thickness design method according to an embodiment of this application.

[0041] Explanation of main component symbols: 1. Adjustable profile fan volute; 10. Volute frame; 11. End cover; 111. Air inlet; 112. Adjustment groove; 1121. Racetrack-shaped slide groove; 1122. Slot; 20. Volute ring wall; 21. Elastic side wall; 210. Drum; 22. Volute tongue; 221. Winding chamber; 222. Guide hole; 23. Spring; 30. Adjusting rod; 31. Screw; 310. Mounting surface; 32. Nut; 33. Magnetic component; 34. Buffer pad; 40. Sealing gasket; 400. Chamfered bevel; 41. Side wall pad; 42. Volute tongue pad; 420. Relief groove.

[0042] The above description of the main component symbols, together with the accompanying drawings and specific embodiments, provides a more detailed explanation of the present invention. Detailed Implementation

[0043] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0044] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation shown in the accompanying drawings.

[0045] The positional relationships are provided only for the convenience of describing the invention and for simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the invention.

[0046] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0047] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0048] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0049] In traditional centrifugal fan testing, whenever test data reveals design deficiencies and a new design solution needs to be attempted, engineers must fabricate a completely new volute. This not only leads to long prototyping times but also significantly increases the testing cycle, thus impacting product time-to-market and significantly increasing centrifugal fan development costs. Therefore, this application provides a method for designing an adjustable profile fan volute, a test fan, and the thickness of magnetic components, which can significantly reduce design iteration time and manufacturing costs.

[0050] Specifically, see the attached document. Figures 1 to 7 As shown, one embodiment of this application provides a test fan, which may include an adjustable fan casing 1 and an impeller (not shown) rotatably disposed on the adjustable fan casing 1, for performing optimization tests on a centrifugal fan. It is understood that the impeller of this application may include, but is not limited to, a shaft, a motor driven and connected to the shaft, and a plurality of blades arranged circumferentially along the shaft; further details will not be elaborated here.

[0051] More specifically, such as Figure 1 and Figure 2As shown, the adjustable fan casing 1 may include a casing frame 10, a casing annular wall 20, and multiple adjusting rods 30. The casing frame 10 includes a pair of end caps 11 spaced apart, each end cap 11 having an air inlet 111 and multiple adjusting grooves 112 arranged around the air inlet 111. The casing annular wall 20 includes an elastic sidewall 21 movably disposed between the two end caps 11 and a volute tongue 22 fixed between the two end caps 11; one end of the elastic sidewall 21 is fixedly connected to the two end caps 11 to form an air outlet with the volute tongue 22; the other end of the elastic sidewall 21 passes sequentially through the multiple adjusting grooves 112 and is wound into the volute tongue 22 to form a roll 210. The two ends of each adjusting rod 30 are respectively adjustablely inserted into the opposing adjusting grooves 112 on the two end caps 11 and located outside the elastic sidewall 21 to adjust the profile of the casing annular wall 20. It is understood that the elastic sidewall 21 mentioned in this application may be implemented as a metal roll or a plastic roll, as long as it can undergo elastic deformation in the radial direction of the air inlet 111. This application will not elaborate further on this.

[0052] It is worth noting that during the testing process using this test fan, each adjusting rod 30 can be fixed in the required position on the corresponding adjusting groove 112 according to the profile design requirements. At this time, the impeller rotates to increase the air pressure inside the volute, causing the elastic sidewall 21 to abut against all the adjusting rods 30 under the action of the air pressure, ensuring that the actual profile of the volute ring wall 20 is consistent with the design profile. After testing and analysis, if it is found that the previous design has shortcomings and a new design scheme needs to be tried, it is only necessary to adjust the fixed position of the adjusting rods 30 on the corresponding adjusting groove 112 according to the new design scheme to achieve the profile adjustment of the volute ring wall 20. There is no need for engineers to process a completely new volute, which helps to significantly shorten the testing cycle, reduce development costs, and avoid affecting the product launch time. Especially in today's increasingly competitive market, the significant reduction in testing cycle and cost will have a positive impact on the company's market position.

[0053] Furthermore, since the other end of the elastic sidewall 21 is rolled up within the volute tongue 22, the circumference of the volute annular wall 20 can be adjusted to meet the needs of different profile design schemes. In other words, when the profile circumference in the profile design scheme becomes shorter, the elastic sidewall 21 can be partially rolled up within the volute tongue 22 to shorten the circumference of the volute annular wall 20; when the profile circumference in the profile design scheme becomes longer, the elastic sidewall 21 can be partially pulled out from the volute tongue 22 to lengthen the circumference of the volute annular wall 20, greatly increasing the flexibility of profile design adjustment.

[0054] According to the above embodiments of this application, as Figure 2 , Figure 5 as well as Figure 6 As shown, the volute annular wall 20 may further include a spring-loaded spring 23 disposed between the drum 210 and the volute tongue 22, for applying a winding torque to the drum 210, so that the other end of the elastic sidewall 21 can automatically wind into the volute tongue 22 under the action of the spring-loaded spring 23, so as to ensure that the elastic sidewall 21 is always in an automatically tensioned state. In this way, when the fixed position of the adjusting rod 30 is adjusted to adjust the annular wall profile, if the annular wall circumference increases, the drum 210 will partially extend out of the volute tongue 22 and abut against the adjusting rod 30 under the action of its own elasticity and the air pressure inside the volute; if the annular wall circumference decreases, the excessively long part of the elastic sidewall 21 will automatically wind back into the volute tongue 22 under the action of the spring-loaded spring 23, and the volute annular wall 20 can still abut against the adjusting rod 30 under the action of its own elasticity and the air pressure inside the volute, thereby realizing the controllable adjustment of the annular wall profile.

[0055] It is worth noting that the volute tongue 22 fixedly disposed between the two end caps 11 in this application has at least two advantages: on the one hand, the arc structure of the volute tongue 22 itself can fit very well with the drum 210, and can accommodate the drum 210 while providing support for the drum 210; on the other hand, even a small deformation of the volute tongue 22 can have a significant impact on the air performance of the centrifugal fan. If the volute tongue structure is adjusted, a more precise structure is required. Therefore, fixing the volute tongue 22 in this application can reduce the impact of the volute tongue 22 on the test structure, so as to improve the accuracy of the profile test.

[0056] Furthermore, since the spring 23 exerts an inward contraction force (referred to as contraction force) on the elastic sidewall 21, while the airflow generated by the impeller rotation exerts an outward expansion force (referred to as expansion force) on the elastic sidewall 21, when the adjusting rod 30 is fixed at a certain position in the adjusting groove 112, the expansion force on the elastic sidewall 21 needs to be greater than the contraction force on the elastic sidewall 21 in order for the elastic sidewall 21 to abut against the adjusting rod 30 to ensure that the volute profile is in a stable state. However, the contraction force on the elastic sidewall 21 is related to the circumference of the ring wall, and for some profile designs with a large ring wall circumference, the larger the ring wall circumference, the greater the contraction force on the elastic sidewall 21, which can easily lead to instability in the profile structure.

[0057] To solve this problem, such as Figure 2 and Figure 6As shown, the volute tongue 22 of this application may have a take-up cavity 221 for accommodating the spool 210 and a guide hole 222 communicating with the take-up cavity 221. The other end of the elastic sidewall 21 passes through the guide hole 222 to be wound into the take-up cavity 221 of the volute tongue 22, so that it can extend or retract into the take-up cavity 221 under the guidance of the guide hole 222. In this way, the elastic sidewall 21 will generate friction with the hole wall of the guide hole 222 during the process of passing through the guide hole 222, thus having a certain self-locking ability, thereby limiting the influence of the shrinkage force on the profile structure and helping to improve the stability of the profile structure.

[0058] According to the above embodiments of this application, as Figure 5 As shown, multiple regulating grooves 112 can be arranged along a basic volute profile to reduce unnecessary slotting and decrease the slotted area on the end cap 11, thereby helping to reduce gas leakage. It is understood that the basic volute profile mentioned in this application can be, but is not limited to, implemented as a logarithmic spiral or an Archimedean spiral, etc., which will not be elaborated further in this application.

[0059] Optionally, such as Figure 7 As shown, the adjustment groove 112 has a racetrack-shaped slide groove 1121 that matches the adjustment rod 30, and multiple slots 1122 that communicate with the racetrack-shaped slide groove 1121 and engage with the adjustment rod 30. Thus, the adjustment rod 30 can slide along the racetrack-shaped slide groove 1121 to engage with different slots 1122, achieving the engagement and fixation of the adjustment rod 30 with the end cover 11, thereby completing the adjustment of the volute profile. It can be understood that, theoretically, with N adjustment grooves 112, each with X slots 1122, the profile-adjustable fan volute 1 of this application can be tested with N... X The adjustable volute profile design allows for testing of a thousand different volute profile designs. For example, if there are ten adjustment slots 112, each with three slots 1122, then the adjustable volute profile design of this application can test a thousand different volute profile designs without waiting for a new volute to be manufactured, thus significantly improving testing efficiency.

[0060] Preferably, such as Figure 5 As shown, the racetrack-shaped chute 1121 extends radially along the air inlet 111 in order to minimize the length of the racetrack-shaped chute 1121 while meeting the requirements for volute profile adjustment, thus helping to reduce gas leakage.

[0061] Optionally, such as Figure 3 and Figure 4 As shown, the adjusting rod 30 may include a screw 31 and a nut 32 that matches the screw 31. The screw 31 passes through the opposing adjusting grooves 112 on the two end caps 11. The nut 32 is threaded to the screw 31 to achieve the positioning and fixing of the adjusting rod 30.

[0062] It is worth noting that, since the cap of the screw 31 and the nut 32 can partially or completely cover the adjustment groove 112, the nut 32 is threadedly connected to the screw 31 to provide positioning and fixation, while also partially or completely blocking the adjustment groove 112, which helps to further reduce gas leakage and improve the performance of the fan.

[0063] Furthermore, in the above embodiments of this application, the elastic sidewall 21 only tends to approach the adjusting rod 30 under the action of the internal air pressure to limit the outer dimension of the annular wall profile through the adjusting rod 30, without restricting the inner dimension of the annular wall profile. This is because if a structural component is set inside the annular wall to limit the inner dimension of the annular wall profile, it will significantly affect the flow field inside the volute, resulting in a significant reduction in the validity of the test results. However, when the annular wall profile of the adjustable fan volute 1 is switched from a small curvature scheme to a large curvature scheme, the elastic sidewall 21 tends to maintain the original curvature. At this time, under the condition of lower power setting, the internal air pressure is small and may not be sufficient to make the elastic sidewall 21 abut against the adjusting rod 30, resulting in the annular wall profile not being adjusted properly, affecting the reliability of the test results.

[0064] To solve this problem, such as Figures 1 to 7 As shown, the adjusting rod 30 of this application magnetically pulls the elastic sidewall 21, so that the elastic sidewall 21 can always abut against the adjusting rod 30, so as to accurately adjust the profile of the volute ring wall.

[0065] For example, such as Figure 3 and Figure 4 As shown, the adjusting rod 30 may further include a magnetic element 33 fixed to the screw 31 and magnetically attracting the elastic sidewall 21, so that the elastic sidewall 21 can be magnetically pulled by the magnetic element 33, so that the elastic sidewall 21 can still abut against the adjusting rod 30 under the low power setting (i.e., the wind pressure inside the volute is small), ensuring that the ring wall profile is adjusted in place.

[0066] It is worth noting that although the elastic sidewall 21 can always abut against the adjusting rod 30 under the magnetic traction of the magnetic component 33, the elastic sidewall 21 can still slide relative to the adjusting rod 30, and will not hinder the change of the annular wall circumference during the profile adjustment process; at the same time, the magnetic component 33 located outside the elastic sidewall 21 will not have an adverse effect on the flow field inside the volute, which is conducive to ensuring the reliability of the test results.

[0067] For example, the elastic sidewall 21 can be implemented as a magnetic component, that is, the elastic sidewall 21 can be made of magnetic materials such as iron or alloys; the magnetic component 33 can be implemented as a magnet, such that the magnetic component 33 and the elastic sidewall 21 generate a magnetic attraction force, so as to pull the elastic sidewall 21 by means of magnetic force.

[0068] Optionally, such as Figure 3 , Figure 4 as well as Figure 7 As shown, the screw 31 has a mounting surface 310 facing the elastic sidewall 21. The magnetic element 33 is attached to the mounting surface 310 of the screw 31, so that the magnetic element 33 is located on the side of the screw 31 adjacent to the elastic sidewall 21, which facilitates better magnetic traction of the elastic sidewall 21. It is understood that the magnetic element 33 of this application can be magnetically attracted or bonded to the mounting surface 310, but is not limited to this.

[0069] It is worth noting that since the surface of the magnetic component 33 is typically planar while the surface of the elastic sidewall 21 is curved, if the elastic sidewall 21 directly contacts the magnetic component 33, the contact method is implemented as line contact, which can lead to stress concentration. This can easily cause concave deformation at the point on the elastic sidewall 21 that contacts the adjusting rod 30, resulting in reduced smoothness of the volute ring wall profile and consequently adversely affecting the accuracy of the test results. To address this issue, such as... Figure 3 , Figure 4 as well as Figure 7 As shown, the adjusting rod 30 of this application may further include a buffer pad 34 attached to the magnetic element 33. The buffer pad 34 is located between the magnetic element 33 and the elastic sidewall 21 to conform to the elastic sidewall 21. In this way, the flexible deformation of the buffer pad 34 can increase the contact area between the adjusting rod 30 and the elastic sidewall 21, which helps to reduce stress concentration and improve the smoothness of the ring wall profile. It is understood that the buffer pad 34 mentioned in this application may be, but is not limited to, made of flexible materials such as silicone or rubber.

[0070] Optionally, such as Figure 3 and Figure 4 As shown, the length of the magnetic element 33 is equal to the width of the elastic sidewall 21; the width of the magnetic element 33 is equal to the diameter of the screw 31.

[0071] Optionally, a notch or groove is provided on the screw 31 at the portion corresponding to the elastic sidewall 21 to accommodate the magnetic component 33, so that the mounting surface 310 is provided through the bottom of the notch or groove, which helps to improve the compactness of the overall structure.

[0072] Optionally, the width of the mounting surface 310 is equal to the diameter of the screw 31, that is, the central axis of the screw 31 lies in the plane where the mounting surface 310 is located, so that the mounting surface 310 can match the cross-section of the magnetic element 33.

[0073] It is worth noting that when setting up magnets, it is generally desirable to use the smallest possible magnets to ensure the compactness of the spatial structure and reduce costs. Since the length and width of the magnetic component 33 in this application have been determined according to the requirements, this application needs to select magnets of appropriate thickness in order to ensure the fit of the elastic sidewall 21 while minimizing the volume of the magnetic component 33.

[0074] Furthermore, to calculate the local curvature of the elastic sidewall 21 caused by the force F acting on it, which changes the curvature from the inner limit curvature a to the outer limit curvature b, based on the beam bending theory in elasticity, the local area of ​​the elastic sidewall 21 can be regarded as a beam, and the calculation will involve bending stress and bending strain. Since the curvature ψ is defined as the reciprocal of the radius of curvature R of the curve at a certain point, i.e. ψ = 1 / R; for beam bending, the change of curvature ψ can satisfy the following relationship (1):

[0075]

[0076] In the formula: E is the elastic modulus (i.e. Young's modulus) of the elastic sidewall 21, which depends on the material selected for the elastic sidewall 21 and is considered known in this application; I is the moment of inertia of the elastic sidewall 21, which can be represented by the width w and thickness v of the elastic sidewall 21; M is the torque of the magnetic element 33 acting on the elastic sidewall 21.

[0077] Optionally, such as Figure 2 As shown, the elastic sidewall 21 has a rectangular cross-section, and its moment of inertia I can satisfy the following relationship (2):

[0078]

[0079] In the formula: w is the width of the elastic sidewall 21; v is the thickness of the elastic sidewall 21.

[0080] Optionally, such as Figure 5 and Figure 6 As shown, the torque M exerted by the magnetic component 33 on the elastic sidewall 21 can satisfy the following relationship (3):

[0081]

[0082] In the formula: F 磁L1 and L2 are the required magnetic force; L1 and L2 are the vertical distances between an intermediate force-bearing point (x2, y2) on the elastic sidewall 21 and the adjacent left force-bearing points (x1, y1) and right force-bearing points (x3, y3), respectively. Specifically, L1 is the distance between the perpendicular line drawn from the intermediate force-bearing point and the line connecting the left and right force-bearing points, and L2 is the distance between the perpendicular line and the left force-bearing point. K1 is a safety factor used to compensate for estimation errors. It is understood that the safety factor K1 mentioned in this application is typically between 0.7 and 1.

[0083] Therefore, to calculate the torque M required to change the elastic sidewall 21 from the inner limiting curvature a to the outer limiting curvature b, we can obtain the following by combining the above formulas (1) and (3):

[0084]

[0085] By arranging the data, we can obtain the magnetic force F required to change the elastic sidewall 21 from the inner limiting curvature a to the outer limiting curvature b. 磁 The following relation (4) must be satisfied:

[0086]

[0087] From the above formula (4), it can be seen that the greater the curvature change (i.e., the larger ba is) and the smaller L1 and L2 are, the greater the required magnetic force. For the entire volute, the curvature change is greatest at the part of the elastic sidewall 21 near the volute tongue 22, and L1 and L2 are smallest at this part. Therefore, when performing design calculations, this application only needs to calculate based on the dimensions of the part of the elastic sidewall 21 near the volute tongue 22.

[0088] It is worth noting that, such as Figure 6 As shown, after determining the slot position and length of the adjustment groove 112, the limit coordinates (i.e., the innermost coordinates and the outermost coordinates) of the middle force point (x2, y2) and the right force point (x3, y3) can be determined by the adjustment rod 30. The left force point (x1, y1) is determined by the position of the volute tongue 22, and its coordinates are fixed. Therefore, the values ​​of L1 and L2 in the above formula (4) are fixed. That is to say, L1 mentioned in this application is the vertical distance between the adjustment rod 30 adjacent to the volute tongue 22 and the volute tongue 22; L2 is the vertical distance between the adjustment rod 30 adjacent to the volute tongue 22 and the adjacent adjustment rod 30.

[0089] Furthermore, obtaining the inner limiting curvature *a* and the outer limiting curvature *b* can be transformed into the following problem: Figure 6As shown, given the coordinates of three points on a spline curve as (x1, y1), (x2, y2), and (x3, y3), find the curvature near the intermediate point of force application (x2, y2). The curvature of a spline curve can be calculated using the following steps: 1) Calculate the first and second derivatives of the spline curve at the intermediate point of force application (x2, y2); 2) Calculate the curvature using the curvature formula based on the first and second derivatives.

[0090] For example, the first derivative of the intermediate stress point satisfies the following relationship (5):

[0091]

[0092] The second derivative of the intermediate stress point satisfies the following relationship (6):

[0093]

[0094] The curvature formula can be implemented as the following relation (7):

[0095]

[0096] Combining the above relationships (5), (6) and (7), and substituting the outermost and innermost coordinates of the adjustment groove 112, the inner limit curvature a and outer limit curvature b of the spline curve at the intermediate stress point can be calculated, that is, the inner limit curvature a and outer limit curvature b of the elastic sidewall 21 at the adjustment rod 30 near the volute tongue 22 can be obtained.

[0097] In the above embodiments of this application, the magnetic force F of the magnetic element 33 on the elastic sidewall 21 磁 It can be estimated using an empirical magnetic force model. Optionally, this empirical magnetic force model can be, but is not limited to, implemented as follows:

[0098]

[0099] Wherein, K2 is an empirical coefficient based on the magnetic element 33; K3 is an empirical coefficient based on the elastic sidewall 21; ρ is the density of the magnetic element 33; L is the length of the magnetic element 33; B is the width of the magnetic element 33; t c The thickness of the magnetic component 33; t h The thickness of the cushioning pad 34.

[0100] It is worth noting that the empirical coefficient K2 mentioned in this application depends on the type of material of the magnetic component 33 itself. For example, the K2 corresponding to a neodymium iron boron magnet is 2*10. -2 Up to 4*10 -2The values ​​can be obtained through tensile testing; the empirical coefficient K3 mentioned in this application depends on the material of the elastic sidewall 21, such as K3 between 0.7 and 0.8 for galvanized sheet; the density ρ mentioned in this application depends on the type of material of the magnetic component 33 itself, such as the density of ferrite magnets being approximately 5*10 3 kg / m 3 Up to 5.5*10 3 kg / m 3 Between these values, the density of neodymium iron boron magnets is typically between 7*10. 3 kg / m 3 Up to 7.3*10 3 kg / m 3 Between; the length L mentioned in this application is generally designed based on the width W of the elastic sidewall 21, which is considered known in this application; the thickness t of the cushioning pad 34 mentioned in this application h The width B of the magnetic element 33 mentioned in this application is usually between 0.002m and 0.005m and is considered known in this application; the width B of the magnetic element 33 mentioned in this application is usually designed based on the diameter of the screw 31 and is considered known in this application.

[0101] Due to the magnetic force F applied by the magnetic component 33 to the elastic sidewall 21 磁 'Requires a magnetic force F greater than or equal to the required force' 磁 ,Right now:

[0102]

[0103] Therefore, the thickness t of the magnetic component 33 c The following relation (8) needs to be satisfied:

[0104]

[0105] In summary, as Figure 4 and Figure 7 As shown, in order to ensure the fit of the elastic sidewall 21 while maintaining the compactness of the spatial structure and reducing costs, the thickness t of the magnetic component 33 in this application is... c The following relationship must be satisfied:

[0106]

[0107] In the formula: t cE is the thickness of the magnetic component 33; E is the elastic modulus of the elastic sidewall 21; I is the moment of inertia of the elastic sidewall 21; b is the outer limit curvature of the elastic sidewall 21 at the adjusting rod 30 adjacent to the volute tongue 22; a is the inner limit curvature of the elastic sidewall 21 at the adjusting rod 30 adjacent to the volute tongue 22; L1 is the vertical distance between the adjusting rod 30 adjacent to the volute tongue 22 and the volute tongue 22; L2 is the vertical distance between the adjusting rod 30 adjacent to the volute tongue 22 and the adjacent adjusting rod 30; t h K1 is the thickness of the buffer pad 34; K2 is the safety factor; K3 is the empirical coefficient based on the magnetic element 33; K3 is the empirical coefficient based on the elastic sidewall 21; ρ is the density of the magnetic element 33; L is the length of the magnetic element 33; and B is the width of the magnetic element 33.

[0108] It is worth noting that, because the other end of the elastic sidewall 21 needs to be rolled up within the volute tongue 22, in order to ensure the flexibility of the overall assembly and the elastic sidewall 21, the actual width of the elastic sidewall 21 usually needs to be smaller than the distance between the two end caps 11. This will cause a large amount of airflow to leak from the gap between the elastic sidewall 21 and the end cap 11, easily causing the test fan to malfunction. To solve this problem, such as... Figure 1 and Figure 2 As shown, the profile-adjustable fan volute 1 of this application may further include a pair of sealing gaskets 40. The two sealing gaskets 40 are respectively fixed to the inner walls of the two end caps 11 and located between the end caps 11 and the volute annular wall 20 to fill the gap between the end caps 11 and the volute annular wall 20, thereby ensuring the sealing effect of the profile-adjustable fan volute 1.

[0109] Optionally, such as Figure 2 and Figure 5 As shown, each sealing gasket 40 includes a sidewall gasket 41 protruding from the end cap 11 and located between the end cap 11 and the elastic sidewall 21. The sidewall gasket 41 extends along the elastic sidewall 21 and has an adjustment hole corresponding to the adjustment groove 112. This hole allows the adjustment rod 30 to pass through while filling the gap between the end cap 11 and the elastic sidewall 21, preventing high-pressure airflow inside the volute from leaking out of the gap between the end cap 11 and the elastic sidewall 21. This helps improve the sealing effect of the profile-adjustable fan volute 1. It is understood that the adjustment hole mentioned in this application may have the same shape as the adjustment groove 112.

[0110] Optionally, such as Figure 2 and Figure 5As shown, each sealing gasket 40 further includes a volute gasket body 42 protruding from the end cap 11 and located between the end cap 11 and the volute tongue 22. The volute gasket body 42 has a relief groove 420 that matches the volute tongue 22, so as to avoid insufficient contact between the elastic sidewall 21 and the sidewall gasket body 41 due to the volute gasket body 42 raising the volute tongue 22, so as to ensure good contact between the elastic sidewall 21 and the sidewall gasket body 41 and ensure good sealing effect.

[0111] Optionally, such as Figure 2 and Figure 5 As shown, the inner edge of the sealing gasket 40 is inclined toward the air inlet 111 to form a chamfered surface 400, so as to reduce the disturbance effect of the sealing gasket 40 on the airflow inside the volute and make the experimental results more reliable.

[0112] It is worth mentioning that, according to another aspect of this application, such as Figure 8 As shown, one embodiment of this application further provides a method for designing the thickness of a magnetic component, which includes the following steps:

[0113] S100: Based on the moment of inertia of the elastic sidewall and the curvature formula of the beam bending, the magnetic force required for the elastic sidewall to change from the inner limit curvature to the outer limit curvature is calculated through a magnetic force calculation model.

[0114] S200: Based on the thickness of the buffer pad and the length, width, and density of the magnetic component, the magnetic force exerted by the magnetic component on the elastic sidewall is calculated using an empirical magnetic force model; and

[0115] S300: Based on the fact that the magnetic force applied by the magnetic component to the elastic sidewall is greater than or equal to the magnetic force required for the elastic sidewall, a thickness relationship is constructed to solve for the thickness of the magnetic component.

[0116] It is worth noting that the magnetic force calculation model mentioned in this application can be implemented as follows:

[0117]

[0118] Wherein: F 磁 The magnetic force required for the elastic sidewall to change from the inner limiting curvature a to the outer limiting curvature b; E is the elastic modulus of the elastic sidewall; I is the moment of inertia of the elastic sidewall; L1 is the vertical distance between the adjusting rod adjacent to the volute tongue and the volute tongue; L2 is the vertical distance between the adjusting rod adjacent to the volute tongue and the adjacent adjusting rod; K1 is the safety factor.

[0119] Furthermore, the empirical magnetic model mentioned in this application can be implemented as follows:

[0120]

[0121] Among them, F 磁' is the magnetic force exerted by the magnetic component on the elastic sidewall; K2 is an empirical coefficient based on the magnetic component; K3 is an empirical coefficient based on the elastic sidewall; ρ is the density of the magnetic component; L is the length of the magnetic component; B is the width of the magnetic component; t c t represents the thickness of the magnetic component. h This refers to the thickness of the cushioning pad.

[0122] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0123] The above embodiments merely illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention.

Claims

1. A fan casing with adjustable profile, characterized in that, include: The volute frame includes a pair of end caps arranged at intervals, each end cap having an air inlet and a plurality of adjustment slots arranged around the air inlet; The volute annular wall includes an elastic sidewall movably disposed between the two end caps and a volute tongue fixedly disposed between the two end caps; one end of the elastic sidewall is fixedly connected to the two end caps to form an air outlet with the volute tongue; the other end of the elastic sidewall passes through a plurality of adjustment grooves in sequence and is wound into the volute tongue to form a roll. as well as Multiple adjusting rods, each having its two ends adjustablely inserted into opposing adjusting slots on two end caps, and located outside the elastic sidewalls, with magnetic force pulling the elastic sidewalls to adjust the profile of the volute annular wall.

2. The adjustable profile fan casing according to claim 1, characterized in that, The adjusting rod includes a screw, a nut that matches the screw, and a magnetic component fixed to the screw and magnetically attracting the elastic sidewall; the screw passes through the two opposing adjusting slots on the end caps, and the nut is threadedly connected to the screw.

3. The adjustable profile fan casing according to claim 2, characterized in that, The elastic sidewall is a magnetic component; the magnetic component is a magnet.

4. The adjustable profile fan casing according to claim 2, characterized in that, The screw has a mounting surface facing the elastic sidewall, and the magnetic element is attached to the mounting surface of the screw.

5. The adjustable profile fan casing according to claim 4, characterized in that, The adjusting rod further includes a buffer pad attached to the magnetic element, the buffer pad being located between the magnetic element and the elastic sidewall to conform to the elastic sidewall.

6. The adjustable profile fan casing according to claim 5, characterized in that, The length of the magnetic component is equal to the width of the elastic sidewall; the width of the magnetic component is equal to the diameter of the screw.

7. The adjustable profile fan casing according to claim 6, characterized in that, A notch or groove is provided on the screw at a location corresponding to the elastic sidewall to accommodate the magnetic component, so that the mounting surface is provided through the bottom of the notch or groove; the width of the mounting surface is equal to the diameter of the screw.

8. The adjustable profile fan casing according to claim 7, characterized in that, The thickness of the magnetic component satisfies the following relationship: ； In the formula: t c E is the thickness of the magnetic component; E is the elastic modulus of the elastic sidewall; I is the moment of inertia of the elastic sidewall; b is the outer limiting curvature of the elastic sidewall near the adjusting rod of the volute tongue; a is the inner limiting curvature of the elastic sidewall near the adjusting rod of the volute tongue; L1 is the vertical distance between the adjusting rod near the volute tongue and the volute tongue; L2 is the vertical distance between the adjusting rod near the volute tongue and the adjacent adjusting rod; t h K1 is the thickness of the buffer pad; K2 is the safety factor; K3 is the empirical coefficient based on the magnetic component; ρ is the density of the magnetic component; L is the length of the magnetic component; and B is the width of the magnetic component.

9. The adjustable profile fan casing according to any one of claims 1 to 8, characterized in that, It also includes a pair of sealing gaskets, which are respectively fixed to the inner walls of the two end caps and located between the end caps and the volute annular wall to fill the gap between the end caps and the volute annular wall.

10. A test fan, characterized in that, include: Adjustable fan casing as described in any one of claims 1 to 9; and An impeller is rotatably mounted on the volute of the profile-adjustable fan.

11. A method for designing the thickness of magnetic components, characterized in that, For the adjustable profile fan casing as described in any one of claims 5 to 9, the steps include: Based on the moment of inertia of the elastic sidewall and the curvature formula of the beam bending, the magnetic force required for the elastic sidewall to change from the inner limit curvature to the outer limit curvature is calculated using a magnetic force calculation model. Based on the thickness of the buffer pad and the length, width and density of the magnetic component, the magnetic force exerted by the magnetic component on the elastic sidewall is calculated using an empirical magnetic force model. as well as Based on the fact that the magnetic force applied by the magnetic component to the elastic sidewall is greater than or equal to the magnetic force required for the elastic sidewall, a thickness relationship is constructed to solve for the thickness of the magnetic component.

12. The magnetic component thickness design method according to claim 11, characterized in that, The magnetic force calculation model is as follows: ； Wherein: F 磁 The magnetic force required for the elastic sidewall to change from the inner limiting curvature a to the outer limiting curvature b; E is the elastic modulus of the elastic sidewall; I is the moment of inertia of the elastic sidewall; L1 is the vertical distance between the adjusting rod adjacent to the volute tongue and the volute tongue; L2 is the vertical distance between the adjusting rod adjacent to the volute tongue and the adjacent adjusting rod; K1 is the safety factor.

13. The magnetic component thickness design method according to claim 11, characterized in that, The empirical model of magnetic force is as follows: ； Among them, F 磁 ' is the magnetic force exerted by the magnetic component on the elastic sidewall; K2 is an empirical coefficient based on the magnetic component; K3 is an empirical coefficient based on the elastic sidewall; ρ is the density of the magnetic component; L is the length of the magnetic component; B is the width of the magnetic component; t c t represents the thickness of the magnetic component. h This refers to the thickness of the cushioning pad.

Images